Dig Deeper

Is It a Bulb?

The Difference Between Bulbs, Corms, Tubers, Roots

Today, people commonly use the term "bulb" to refer to any plant that stores its own food underground. But, in truth, many popular "bulbs" are not true bulbs at all. These include corms, tubers and roots and, while they all produce beautiful flowers, technically the plants are different.

Bulbs and corms look quite similar. Bulbs store their food in their scales while corms store food in their basal plate. For that reason, corms have smaller scales and an enlarged basal plate. This gives corms a flatter shape versus the rounder shape of bulbs. Examples of corms are crocuses and gladioli.

Tubers and roots come in a variety of shapes including cylindrical and flat. Many come in clusters and have no protective tunic.

Tubers and roots are really just enlarged stem tissue. Familiar tubers include dahlias and begonias.